What it means
The current ratio counts all current assets against current liabilities, but inventory is not always convertible into cash quickly or at book value. Seasonal stock, specialised components and slow-moving lines may take months to sell and may fetch less than they cost.
The acid test removes inventory and asks the harder question: if creditors had to be paid tomorrow and nothing could be sold, could the business cope? A business that passes the acid test is liquid in a way that does not depend on its trading continuing normally.
The interpretation depends on the industry. A supermarket or restaurant turns inventory into cash within days and collects most sales in cash, so it can run an acid test of 0.3 or 0.4 without difficulty; its current liabilities are paid from a continuous flow of takings.
An engineering firm whose stock takes months to convert and whose customers pay in 60 days needs a ratio close to or above 1.0 to be safe. Comparison with industry norms and with the company's own history is essential; a single benchmark applied to every business misleads.
The quality of the receivables in the numerator also matters. A receivable from a customer in financial difficulty is not a quick asset, and a large balance that is 120 days overdue should be excluded or discounted.
Analysts adjust the acid test for doubtful debts and look at the receivables ageing alongside it. They also read it with the cash ratio, which excludes receivables altogether, to see how much of the business's liquidity depends on customers paying.
The ratio is a point-in-time measure and can be managed around a balance sheet date by delaying purchases or accelerating collections. Lenders who use it as a covenant typically test it quarterly or monthly, and sophisticated readers look at the trend over several periods rather than one figure.
In practice
Real-world examples.
Example
A bank sets a covenant requiring a borrower's acid test to stay above 0.8, tested quarterly, because the borrower's inventory is specialised and slow to sell.
Example
A distributor's acid test falls from 0.9 to 0.5 after a large customer goes into administration, because $1.5 million of receivables has to be written off.
Example
A cash-rich technology company reports an acid test of 3.5, which analysts read as excess cash that could be returned to shareholders.
Think of it
“The acid test strips out inventory to show if you can pay bills with truly liquid assets.
Formula
Calculation
Acid Test (Quick) Ratio = (Cash + Marketable Securities + Accounts Receivable) / Current Liabilities
or: (Current Assets minus Inventory minus Prepaid Expenses) / Current Liabilities
Worked example. A furniture retailer and a software company both report current liabilities of $2,000,000.
Furniture retailer: cash $200,000; receivables $300,000 (mostly finance company balances); inventory $2,400,000; prepayments $100,000.
- Current ratio = ($200,000 + $300,000 + $2,400,000 + $100,000) / $2,000,000 = 1.50
- Acid test = ($200,000 + $300,000) / $2,000,000 = 0.25
Software company: cash $1,500,000; receivables $900,000; no inventory; prepayments $150,000.
- Current ratio = ($1,500,000 + $900,000 + $150,000) / $2,000,000 = 1.28
- Acid test = ($1,500,000 + $900,000) / $2,000,000 = 1.20
On the current ratio the retailer looks stronger. On the acid test the software company is far more liquid: it could pay every current liability from cash and receivables with room to spare, while the retailer depends on selling furniture to pay its bills. For the retailer that is normal, provided stock keeps selling; the acid test shows what would happen if it did not.
Adjustment: if $200,000 of the software company's receivables is a disputed balance from a customer that has stopped paying, the adjusted acid test is ($1,500,000 + $700,000) / $2,000,000 = 1.10, still comfortable.Case study
Seen in the real world.
A regional homebuilder reported a current ratio of 2.4, and its board considered the company highly liquid. Nearly all of its current assets, however, were land and houses under construction, classified as inventory. When mortgage rates rose and sales slowed, the builder could not convert that inventory to cash fast enough to pay contractors and interest.
Its acid test, which had been 0.15, had told the story: the company had $2 million of cash and receivables against $13 million of current liabilities, and everything else depended on selling houses on schedule. The company survived by negotiating extended terms with its main contractors and a bridging facility secured on completed homes, at considerable cost. The board now reviews the acid test monthly and requires cash plus committed facilities to cover six months of fixed costs, regardless of how healthy the current ratio looks.
Watch out
Common mistakes.
- Treating an acid test below 1.0 as a problem in every business. Cash-sales businesses with fast-moving stock operate safely well below it.
- Including doubtful or overdue receivables in quick assets.
- Reading one year-end figure. The ratio can be managed on a single date; the trend and interim figures matter more.
Questions
People also ask.
What is a good acid test ratio?
Around 1.0 is a common benchmark for businesses with credit sales and slow-moving stock; lower is acceptable where inventory turns quickly and sales are for cash.
How is the acid test different from the current ratio?
The current ratio includes inventory and prepaid expenses; the acid test excludes them, testing liquidity without relying on stock being sold.
Why is it called the acid test?
After the method of testing gold with acid, meaning a quick and definitive test of quality.
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